The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 01, 2000
Filed:
Dec. 23, 1998
Henry M Beisner, Rockville, MD (US);
Robert Harold Benner, Gaithersburg, MD (US);
Jack George Rudd, Boulder, CO (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
In a global monitoring system having four or more satellites which transmit messages to user stations by which the user stations can determine the user position, the satellite messages include the time of transmission of the messages as indicated by satellite clocks and includes a correction message. The correction message consists of time correction values for the satellite clocks. The satellite time correction values are determined from a clocks only model wherein three or more monitoring stations having known positions on the ground receive the satellite messages and determine pseudoranges between the satellites and the monitoring stations. The satellite time correction values are determined statistically by nonlinear least squares from a clocks only model relating the ranges between the satellites and the monitoring stations to the measured pseudoranges, the satellite time correction values and monitoring stations time correction values.